The NP205 gear
driven transfer case is considered by many to be the king of
bulletproof. It was supplied in many GM, Ford, International and Dodge
full-size trucks. Here is a documented tear down and rebuild of this
unit. This can be done without a press, and with basic tools. Follow along and look at the photos provided then you will be
ready to do this rebuild on your NP-205.

11. Using a rubber mallet, tap the front output shaft assembly from the case.

12. Remove the snap ring from the front output shaft bearing and remove bearing from case.

13.Remove the 4 bolts from the input shaft seal retainer, and remove retainer from case.

14. Remove the 8 bolts from the rear drive output shaft assembly.

15. Remove assembly from case.

16. There are 15 roller bearings in the assembly, put them in a small ziplock bag.

17. Remove the snap ring from the input shaft bearing.

18. From inside the case, grab the input shaft assembly and pull the assembly out.
Note: Tapping on the input shaft with a small hammer will ease removal.

19. Using a blunt punch, drive the two 1/4 inch shift rail pin access hole plugs into the case.

20. Remove the two shift rail poppet nuts and springs from the case.

21. There is a ball bearing in each hole that can be removed using a slim magnet.
Note: If no magnet is available, you can tilt the case over and the ball bearings will fall out.

22. Position both shift rails in neutral to line up the shift fork retaining pins.

23. Using a narrow punch, tap the shift fork retaining pins out.
Note: Pins will fall to the bottom of the case.

24. Remove the range shift rail (short one) first, then the 4 wheel drive rail (long one).
Note: When you remove the rails hold the shifter forks with the other hand and remove them from the case. Keep them together.

25. Slide the rail pins out.

26. Remove the idler shaft lock nut.
Note: An impact wrench can be used for this. It is a 1- 5/16 nut so make sure you have this size socket.

27. Remove the washer behind the lock nut.

28. Remove the idler shaft rear cover.

29. Use a punch and mallet to drive the idler shaft out.

30. Roll the idler shaft assembly to the right and pull it out of the large hole.

31. Remove the PTO access cover.
Note: At this point you are finished with tear down. If you are going to paint your case, this is the time to do that.

32. Pull the shift rail seals.

33. During tear down, it is a good idea to keep the parts from each assembly together in bags.

34. Assembly begins with a freshly painted case.

35. If you need new bearings in the idler shaft assembly, drive out the old races and put new ones in.
Note: It will cost substantially less to rebuild if you don't have to replace all your bearings.

36. Here is all the parts for the idler shaft assembly.

37. Start with one of the bearings on a piece of cardboard.
Note: There are 4 shims in the assembly. Two of them go on top of this bearing.

38. Place the idler gear on top of the bearing.

39. Place the spacer on the bearing and shims. Place the other 2 shims on the top of the spacer.

40. Place the other bearing into the race.

41. Slide the assembly to the end of your workbench and place your hand under the cardboard.

42. Place the assembly into the large hole keeping the cardboard underneath.

43. Slide assebly to the left until centered on the hole, then remove cardboard.

44. Place idler shaft into hole and lightly tap until it drops through.

82. Flip upside down and using a long needle nose plier and petroleum jelly, install needle bearings.
Note: There is a spacer that must be placed under the needle bearings, use a pic to hold it up while inserting bearings.

83. Set case on its side supporting one side with a 4"x4" wood block.

84. Apply gasket sealer to both sides of gasket and drop assembly into place.
Note: Try to line up the bolt holes before setting into place, you might have to use a hammer to tap it into place.